- Patients eligible for pancreatic islet transplantation based on local accepted practice and guidelines. This includes at least: a)clinical history compatible with T1D with insulin-dependence for >5 years; b) undetectable stimulated (arginine or MMTT) C-peptide levels (<0.3 ng/mL) in the 12 months before transplant. Sites will comply with any additional or more stringent criteria locally accepted, as per centre practice.